In modern data communication systems, security is one of the major problems. With more and more information being transferred over data communication systems and more and more user applications with security critical information are running on devices connected to such communication systems the intrusion into a communication system or the breaking of security related mechanism may have disastrous implications. In order to prevent attacks or intrusions by hostile users, the user is requested in many communication networks to authenticate before starting a data communication via an access node of the communication network. Various mechanisms for authentication are known for example the authentication process according to Institute of Electrical and Electronics Engineers (IEEE) 802.1X. On the other hand, modern data communication requires having an access to the communication network as easy as possible and as quick as possible. Existing communication networks, e.g. authentication mechanism such as the IEEE 802.1X, may provide secure authentication but consume quite some time in providing the authentication.